Since the discovery of the disease, Apparent Mineralocorticoid Excess (AME), in 1977 by Dr. New, the enzymatic defect (11beta-hydroxysteroid dehydrogenase type II) causing the disease has been described. Recently, mutations in the gene encoding the enzyme have been described. The phenotype of the disease includes failure to thrive in early childhood, hypertension, hypokalemia, suppressed renin, and low secretion of all adrenal steroids. Recently, an exception to this phenotype has been found, in an inbred population. We plan to investigate the prevalence of the disease and the mutations in this population. As the disease has a high fatality rate, we plan to carry out long-term follow-up and treatment of patints investigated earlier in our Children's Clinical Research Center. Pre-emptive renal transplantation for patients with AME will be investigated as a new form of treatment.